Current Event: Get Your Flu Shot Now, Health Officials Urge

Officials at the United States Centers for Disease Control and Prevention (CDC) are finding that vaccines administered this year to protect people from influenza (the flu) are not as effective as they had hoped. However, the CDC still urged people to get a flu shot. Health official said that in addition to feeling miserable, people with the flu might develop flu-related complications that may lead to hospitalization and death. Global flu outbreaks occur each year, usually in winter months. Because of mutations, the viruses causing an outbreak are slightly different from those associated with earlier outbreaks. Vaccine manufacturers must produce flu vaccine months before any outbreak in order to ensure sufficient vaccine supplies when flu season hits. In order to do that, the manufacturers must predict which flu strains (types) are likely to cause that year’s outbreak. However, CDC scientists found that fewer than half of the flu virus samples obtained from patients from October and November 2014 matched any of the strains used to make this year’s vaccines. Nevertheless, medical experts note that even if a vaccine does not exactly match the most common strains of flu circulating, the vaccine still provides significant protection. CDC officials stressed that over the years, hundreds of millions of Americans have safely received flu vaccines.

Influenza viruses may cause flu when they are inhaled. The viruses shown here are greatly magnified and artificially colored. (© Linda Stannard, UCT/SPL from Photo Researchers)

Objective:

Influenza (the flu) is an infectious disease caused by the influenza virus. The symptoms of influenza include chills, fever, headache, body aches, and weakness. The symptoms usually disappear in about a week. The disease may lower a patient’s resistance, so that secondary infections, such as bacterial pneumonia, follow. Influenza is mainly a respiratory disease. The virus is inhaled and comes in contact with cells of the upper air passages. It penetrates the cells that line these passages and reproduces. In time, new viruses are released from the infected cells and infect other cells along the respiratory tract. The virus may also be carried away in exhaled air and infect other people. People may also become infected by touching something with the virus on it and then touching their mouth or nose. Simple hygiene practices, such as frequent hand washing, can help control the spread of influenza. However, the most effective means to prevent the spread of the disease is through vaccination. The Behind the Headlines news story and related World Book articles explore influenza and other diseases.

Words to know:

• Centers for Disease Control and Prevention (CDC)
• Disease
• Epidemic
• Immune system
• Immunization
• Influenza
• Mutation
• Virus

Discussion Topics:

1. Ask your students to name other diseases caused by viruses. (Students might say AIDS, chickenpox, Ebola, measles, mumps, rabies, smallpox, and yellow fever.)

2. Occasionally, a school will cancel classes for a few days due to a flu outbreak or some other illness. Ask your students to debate, “When should a school cancel classes due to illness?”

3. Ask your students to use World Book’s Timelines feature to view or add to the Advances in Medicine timeline. (Students may wish to use the “History” section of World Book’s “Medicine” article for help.)